The intent of this conference is to bring together scientists of various disciplines who are in the forefront of research related to estrogen biosythesis and its significance regarding hormonedependent cancer and reproduction. This will be the second major conference related to this topic. On December 6th9th, 1981, the conference "Aromatase - New Perspectives for Breast Cancer" was held at Key Biscayne, Florida. This meeting assembled approzimately one hundred investigators for a multidisciplinary interchange regarding this critical enzyme in estrogendependent disease processes. Proceedings of this conference were published in Cancer Research, 42:3261s, 1982. This publication has become a bench mark in aromatase research. During the past five years a significant expansion has occurred in "aromatase" science including enzyme purification and regulation, development of cDNA clones, understanding on physiology, and development of enzymatic inhibitors. One year ago, a group of investigators developed the concept for a second meeting entitled "Aromatase - Future Perspectives". This meeting will address various scientific aspects that encompass the scope of both basic and applied research. The enzyme aromatase is critically important in the generation of estradiol, the predominant hormonal stimulator of the growth of endocrinedependent breast cancer. Approximately one hundred thousand new cases are diagnosed yearly and aromatase inhibitors have been shown to be efficacious in the treatment of a subset of patients with breast cancer. Endometrial carcinoma occurs with a higher incidence in patients who are obese and have a higher level of peripheral aromatase activity. Treatment with aromatase inhibitors may be beneficial for this type of cancer also. Considerable recent interest has developed regarding the role of estrogens in prostatic carcinoma and in detection of aromatase activity in prostatic tissue. It has been proposed that aromatase inhibitors may be important for this neoplasm. Finally, aromatase may be important in several benign conditions including endometriosis, precocious puberty, premature labor and gynecomastia. Recent advances in the aromatase field, the important clinical significance of aromatase, and the recent development of new inhibitors of this enzyme provide a compelling rationale for an international meeting on this subject.